DJI Has released a 5.8Ghz Tx Rx and cloverleaf antenna set. There is a specific mount for these on the S-800 http://www.foxtechfpv.com/dji-58g-cloverleaf-antenna-on-the-txrx-p-755.html
And the Tx is like 500 Mw which is huge output for that band, I have seen 1,200 Mw also but that seems insane. We are getting solid links at 10+ miles at 200 Mw for 5.8 Ghz data at my job. Big antennas, but full 100 Mega Bit links.
That setup is only $209 at UAV Products too. Add the antennas from the link you posted and you're at $270 for a really nice FPV system.